The field of the present invention is mechanical apparatus and methods for deterring birds from landing at undesirable perch locations.
Historically, birds have been a constant pest to all types of structures and activities of man. Particularly trouble-some are areas with large populations of swallows, seagulls, and pigeons. These unwelcome birds create unwanted noise and their droppings are an unsightly testimony to their presence on public structures and private residences. The bird droppings also present a threat to human health. Fungi in the bird droppings can transmit diseases to humans, with potentially fatal consequences to those suffering from diabetes, blood diseases or a respiratory disease.
Therefore, numerous methods and devices have been utilized to keep birds away from areas where the birds are known to roost and build their nests. Most methods have utilized inanimate devices comprised of a continuous metal strip with sharp, protruding spikes. These, however, must be accurately placed on the nesting area to be effective. The design of the metal strip itself is conductive to nest building by the more industrious of the pests, due to its general shape and immobility. Such devices are also injurious to the birds who impale their wings onto the sharp spikes and are potentially injurious to humans who unknowingly venture too close. Other inanimate devices include certain chemical gels that are applied to the nesting area and mock predators, but these have a limited life span, as the gel will eventually wear off and the mock predators will lose their deterrence effect over time. Reference is herein made to a patent application Ser. No. 07/557,411, filed by the same inventor on Jul. 23, 1990, entitled "BIRD DETERRENT METHOD AND DEVICE," which discloses a non-rotatable bird deterrent. That reference is hereby incorporated by reference herein.
The devices that are electrically powered have their drawbacks as well. A popular device is an electrified wire draped strategically around the nesting or perching area of the birds. These have been used at public buildings, but their high installation cost prohibits use at residences or smaller public facilities. Also, there is the constant cost of keeping the wires electrified and the potential for injury to humans.
Noise deterrent devices have been used but these also annoy the human occupants of the building or residence. Ultrasound emitters effectively deter birds but also household pets, such as cats and dogs, and thus are not real solutions. Another device emits an intermittent flash of light that is disruptive to the birds. This device is ineffective for exterior areas during daylight hours and requires constant upkeep.
Others have employed real life predators such as falcons to get rid of the bird pests. These are unreliable over the long run and do not address the problem of the offensive mess left by the predator itself. Still others have employed the particularly offensive method of shooting large numbers of the offending birds only to have others replace the killed pests.
A need has arisen for an efficient and reliable self-propelled mechanical device which can be utilized at public buildings and private residences, is easy to assemble, but is not injurious to the birds or offensive or injurious to humans.